regmap: Convert regmap_irq to use irq_domain

This gets us up to date with the recommended current kernel infrastructure
and should transparently give us device tree interrupt bindings for any
devices using the framework. If an explicit IRQ mapping is passed in then
a legacy interrupt range is created, otherwise a simple linear mapping is
used. Previously a mapping was mandatory so existing drivers should not
be affected.

A function regmap_irq_get_virq() is provided to allow drivers to map
individual IRQs which should be used in preference to the existing
regmap_irq_chip_get_base() which is only valid if a legacy IRQ range is
provided.

Signed-off-by: Mark Brown <[e-mail]>

drivers/base/regmap/regmap-irq.c

···
 #include <linux/regmap.h>
 #include <linux/irq.h>
 #include <linux/interrupt.h>
+#include <linux/irqdomain.h>
 #include <linux/slab.h>
 
 #include "internal.h"
···
 	struct regmap_irq_chip *chip;
 
 	int irq_base;
+	struct irq_domain *domain;
 
 	void *status_reg_buf;
 	unsigned int *status_buf;
···
 struct regmap_irq *irq_to_regmap_irq(struct regmap_irq_chip_data *data,
 				     int irq)
 {
-	return &data->chip->irqs[irq - data->irq_base];
+	return &data->chip->irqs[irq];
 }
 
 static void regmap_irq_lock(struct irq_data *data)
···
 {
 	struct regmap_irq_chip_data *d = irq_data_get_irq_chip_data(data);
 	struct regmap *map = d->map;
-	const struct regmap_irq *irq_data = irq_to_regmap_irq(d, data->irq);
+	const struct regmap_irq *irq_data = irq_to_regmap_irq(d, data->hwirq);
 
 	d->mask_buf[irq_data->reg_offset / map->reg_stride] &= ~irq_data->mask;
 }
···
 {
 	struct regmap_irq_chip_data *d = irq_data_get_irq_chip_data(data);
 	struct regmap *map = d->map;
-	const struct regmap_irq *irq_data = irq_to_regmap_irq(d, data->irq);
+	const struct regmap_irq *irq_data = irq_to_regmap_irq(d, data->hwirq);
 
 	d->mask_buf[irq_data->reg_offset / map->reg_stride] |= irq_data->mask;
 }
···
 	for (i = 0; i < chip->num_irqs; i++) {
 		if (data->status_buf[chip->irqs[i].reg_offset /
 				     map->reg_stride] & chip->irqs[i].mask) {
-			handle_nested_irq(data->irq_base + i);
+			handle_nested_irq(irq_find_mapping(data->domain, i));
 			handled = true;
 		}
 	}
···
 	else
 		return IRQ_NONE;
 }
+
+static int regmap_irq_map(struct irq_domain *h, unsigned int virq,
+			  irq_hw_number_t hw)
+{
+	struct regmap_irq_chip_data *data = h->host_data;
+
+	irq_set_chip_data(virq, data);
+	irq_set_chip_and_handler(virq, &regmap_irq_chip, handle_edge_irq);
+	irq_set_nested_thread(virq, 1);
+
+	/* ARM needs us to explicitly flag the IRQ as valid
+	 * and will set them noprobe when we do so. */
+#ifdef CONFIG_ARM
+	set_irq_flags(virq, IRQF_VALID);
+#else
+	irq_set_noprobe(virq);
+#endif
+
+	return 0;
+}
+
+static struct irq_domain_ops regmap_domain_ops = {
+	.map	= regmap_irq_map,
+	.xlate	= irq_domain_xlate_twocell,
+};
 
 /**
  * regmap_add_irq_chip(): Use standard regmap IRQ controller handling
···
 			struct regmap_irq_chip_data **data)
 {
 	struct regmap_irq_chip_data *d;
-	int cur_irq, i;
+	int i;
 	int ret = -ENOMEM;
 
 	for (i = 0; i < chip->num_irqs; i++) {
···
 			return -EINVAL;
 	}
 
-	irq_base = irq_alloc_descs(irq_base, 0, chip->num_irqs, 0);
-	if (irq_base < 0) {
-		dev_warn(map->dev, "Failed to allocate IRQs: %d\n",
-			 irq_base);
-		return irq_base;
+	if (irq_base) {
+		irq_base = irq_alloc_descs(irq_base, 0, chip->num_irqs, 0);
+		if (irq_base < 0) {
+			dev_warn(map->dev, "Failed to allocate IRQs: %d\n",
+				 irq_base);
+			return irq_base;
+		}
 	}
 
 	d = kzalloc(sizeof(*d), GFP_KERNEL);
···
 		}
 	}
 
-	/* Register them with genirq */
-	for (cur_irq = irq_base;
-	     cur_irq < chip->num_irqs + irq_base;
-	     cur_irq++) {
-		irq_set_chip_data(cur_irq, d);
-		irq_set_chip_and_handler(cur_irq, &regmap_irq_chip,
-					 handle_edge_irq);
-		irq_set_nested_thread(cur_irq, 1);
-
-		/* ARM needs us to explicitly flag the IRQ as valid
-		 * and will set them noprobe when we do so. */
-#ifdef CONFIG_ARM
-		set_irq_flags(cur_irq, IRQF_VALID);
-#else
-		irq_set_noprobe(cur_irq);
-#endif
+	if (irq_base)
+		d->domain = irq_domain_add_legacy(map->dev->of_node,
+						  chip->num_irqs, irq_base, 0,
+						  &regmap_domain_ops, d);
+	else
+		d->domain = irq_domain_add_linear(map->dev->of_node,
+						  chip->num_irqs,
+						  &regmap_domain_ops, d);
+	if (!d->domain) {
+		dev_err(map->dev, "Failed to create IRQ domain\n");
+		ret = -ENOMEM;
+		goto err_alloc;
 	}
 
 	ret = request_threaded_irq(irq, NULL, regmap_irq_thread, irq_flags,
 				   chip->name, d);
 	if (ret != 0) {
 		dev_err(map->dev, "Failed to request IRQ %d: %d\n", irq, ret);
-		goto err_alloc;
+		goto err_domain;
 	}
 
 	return 0;
 
+err_domain:
+	/* Should really dispose of the domain but... */
 err_alloc:
 	kfree(d->mask_buf_def);
 	kfree(d->mask_buf);
···
 		return;
 
 	free_irq(irq, d);
+	/* We should unmap the domain but... */
 	kfree(d->mask_buf_def);
 	kfree(d->mask_buf);
 	kfree(d->status_reg_buf);
···
  */
 int regmap_irq_chip_get_base(struct regmap_irq_chip_data *data)
 {
+	WARN_ON(!data->irq_base);
 	return data->irq_base;
 }
 EXPORT_SYMBOL_GPL(regmap_irq_chip_get_base);
+
+/**
+ * regmap_irq_get_virq(): Map an interrupt on a chip to a virtual IRQ
+ *
+ * Useful for drivers to request their own IRQs.
+ *
+ * @data: regmap_irq controller to operate on.
+ * @irq: index of the interrupt requested in the chip IRQs
+ */
+int regmap_irq_get_virq(struct regmap_irq_chip_data *data, int irq)
+{
+	return irq_create_mapping(data->domain, irq);
+}
+EXPORT_SYMBOL_GPL(regmap_irq_get_virq);

drivers/mfd/Kconfig

···
 
 config MFD_DA9052_SPI
 	bool "Support Dialog Semiconductor DA9052/53 PMIC variants with SPI"
+	select IRQ_DOMAIN
 	select REGMAP_SPI
 	select REGMAP_IRQ
 	select PMIC_DA9052
···
 
 config MFD_DA9052_I2C
 	bool "Support Dialog Semiconductor DA9052/53 PMIC variants with I2C"
+	select IRQ_DOMAIN
 	select REGMAP_I2C
 	select REGMAP_IRQ
 	select PMIC_DA9052
···
 	bool "Support Wolfson Microelectronics WM8994"
 	select MFD_CORE
 	select REGMAP_I2C
+	select IRQ_DOMAIN
 	select REGMAP_IRQ
 	depends on I2C=y && GENERIC_HARDIRQS
 	help

include/linux/regmap.h

···
 			struct regmap_irq_chip_data **data);
 void regmap_del_irq_chip(int irq, struct regmap_irq_chip_data *data);
 int regmap_irq_chip_get_base(struct regmap_irq_chip_data *data);
+int regmap_irq_get_virq(struct regmap_irq_chip_data *data, int irq);
 
 #else